NEW YORK - Wall Street showed clear relief Monday over the government's plan to bail out Citigroup Inc. - a move it hopes will help quiet some of the uncertainty hounding the financial sector and the overall economy. The major indexes jumped more than 3.5 percent, extending Friday's big rally.

While the markets anticipated last week that some sort of rescue could occur, investors appeared emboldened by the U.S. government's decision late Sunday to invest $20 billion in Citigroup and guarantee $306 billion in risky assets.

The market is also a little more optimistic because President-elect Obama is scheduled to introduce his economic team on Monday and has called for another economic stimulus. His plan targets saving or creating 2.5 million jobs during the next two years. Any plan is expected to exceed the $175 billion Obama proposed during the campaign.

Photo by Craig Ruttle / Associated PressFlags wave in the wind at the Citigroup Center in New York Monday morning. Rushing to rescue Citigroup, the U.S. government agreed to shoulder hundreds of billions of dollars in possible losses at the stricken bank and to plow a fresh $20 billion into the company.

The plan by the Treasury Department, the Federal Reserve and the Federal Deposit Insurance Corp. is only the latest effort this year to support a banking system troubled by bad debt and flagging confidence. Besides implementing its $700 billion bailout plan for the overall financial industry, the government has bailed out insurance giant American International Group Inc. and taken over lenders Fannie Mae and Freddie Mac.

The moves by the government to again step in and help a troubled bank as well as perhaps the broader economy helped buoy investor sentiment. Still, despite the size of Monday's gain, investors remain cautious because the nation faces a difficult economy and the stock market likely will continue to see volatility.

Jim Baird, chief investment strategist with Plante Moran Financial Advisors, said Wall Street is relieved by the government's decision to help prop up Citigroup but he predicted that the initial enthusiasm could give way to further questions about the effectiveness of the government's array of efforts to sew up problems in the financial sector.

"I think, at a minimum, what you're seeing today is some relief that, first of all, they're stepping in to do something," he said. "There's still more questions than answers surrounding whether what's been done is going be enough."

In late morning trading, the Dow Jones industrial average rose 301.63, or 3.75 percent, to 8,348.05.

The rise in stocks follows a rally Friday that saw the Dow industrials jump 494 points, or 6.5 percent. The other major indexes also rose sharply. Still, stocks ended the week with a loss after heavy selling Wednesday and Thursday.

Bond prices were mixed Monday as investors examined the government's bailout plan for Citigroup. The yield on the benchmark 10-year Treasury note, which moves opposite its price, rose to 3.30 percent from 3.20 percent late Friday.

The Treasury bill market showed continuing high demand, a sign of investors' caution. The yield on the three-month T-bill, considered one of the safest investments, fell to 0.02 percent from 0.04 percent late Friday.

The dollar was mostly lower against other major currencies, while gold prices rose.

Baird said the uncertainty over whether the government's cocktail of direct investments in financial houses and support of debt obligations will prove effective has led to the stock market volatility. The concerns about banks and the broader economy are likely to continue, he said.

"Just the sheer breadth of potential outcomes is very, very wide which I think makes it difficult for investors to determine how do you play it from here."

Wall Street shrugged off a larger-than-expected drop in sales of existing homes last month as investors instead focus on the government's rescue for Citigroup. And while the housing numbers fell short of expectations, Wall Street expected sales would fall sharply after last month's upheaval in the financial markets.

The National Association of Realtors says sales of existing homes fell 3.1 percent to a seasonally adjusted annual rate of 4.98 million in October. That's down from 5.14 million in September.

Citi shares surged $2.23, or 59 percent, to $6 on word of the government's injection of capital into the company.

Health care company Johnson & Johnson said Monday it would acquire Omrix Biopharmaceuticals Inc. for $438 million. The move is aimed at expanding J&J's surgical product unit; J&J will pay $25 per share for the company, an 18 percent premium over Omrix's close Friday of $21.16.